Fluid supply device



Jan. 27, 1970 J. PICKLES ET AL FLUID SUPPLY DEVICE Filed April 4, 1966 INVENTORS JOSEPH PICKLES JOSEPH C. ITTMANN FlG.

United States Patent US. Cl. 137563 7 Claims ABSTRACT OF THE DISCLOSURE A compact unitary device for delivering fluid into an external closed system and maintaining the pressure in the system at a pressure variable with an extraneous parameter, comprising a support body having a motor afiixed to one side, an apertured intermediate plate fixed to the other side of the support, and a closure plate fixed to the outside of the intermediate plate. The aperture in the intermediate plate receives pump gears directly connected to the motor shaft. A cup-like reservoir is connected to the cover plate. The pump chamber has an inlet passage extending through the cover plate, intermediate plate, and support body, and an outlet passage connected to a return flow passage to the reservoir and to an outside delivery port. The solenoid carried by the support body regulates a pressure valve in the return passage to the reservoir.

It is an object of the present invention to provide a device of the character described comprising a unitary assembly of an electric motor, reservoir, pump, and valve system for delivering fluid at a controlled pressure into a closed system.

It is a further object of the present invention to provide a device as described in the preceding paragraph comprising a solenoid actuated pressure regulating valve in which the solenoid is adapted to be subjected to a voltage variable in accordance with an extraneous parameter.

It is a further object of the present invention to provide a device of the character described comprising an elongated generally cylindrical assembly comprising an electric motor having a cylindrical casing at one end, a cylindrical reservoir at the other end, and a combined pumping and valving unit intermediate said ends and forming the connection therebetween.

It is a further object of the present invention to provide a device for delivering fluid under a controlled pressure comprising three members having adjacent flat surfaces assembled together in surface-to-surface relation, the intermediate member having an elongated recess in which pump gears are mounted, one of the outer members having an open fluid delivery passage and a return passage having a solenoid controlled pressure regulating valve.

Other objects and features of the invention will become apparent as the description proceeds, especially when taken in conjunction with the accompanying drawing, illustrating a preferred embodiment of the invention, wherein:

FIGURE 1 is an elevational view of the device, partly in section, on the line 11, FIGURE 3.

FIGURE 2 is an elevational view of the device shown in FIGURE 1, taken at a different angle.

FIGURE 3 is a sectional view of the device taken on the line 33, FIGURE 1.

FIGURE 4 is a sectional view of the device taken on the line 4-4, FIGURE 3.

The compact unitary fluid supply device disclosed herein has been designed primarily as means for supplying hydraulic fluid under pressure to a hydraulic brake system and for controlling the pressure of the fluid in the system in accordance with an extraneous parameter. An

3,491,793 Patented Jan. 27, 1970 ICC impotrant use of the present invention is in a trailer brake system in which the device is mounted on the trailer and is connected to the trailer brake system, the extraneous parameter being variable in accordance with the elfectiveness of the brake applied to the tractor or towing vehicle, as for example, pressure variations in the hydraulic brake system thereof.

Described in general terms, the present invention comprises a unitary electric motor, reservoir, pump, pressure control valve, and solenoid valve actuating means, characterized in the efficient utilization of space and the efficient design of flow control passages therein. It is further characterized in a unitary arrangement in which the pump and pressure regulating valve system is supported between and interconnects the cylindrical motor casing and a cylindrical cup which forms the major portion of a fluid reservoir.

Referring now to the drawings, the device comprises a support body 10 which may conveniently be a casting of generally cylindrical configuration, although as seen in FIGURE 3, it is provided with a lateral extension 12 having flat surfaces 14 and 16. The body 10 has a central opening 18 therethrough for receiving the shaft 20 of an electric motor 22 provided with a cylindrical casing 24. The body 10 has a flat surface 25 in which is provided a relatively shallow inlet recess 26 and a relatively deeper outlet recess 28. The outlet recess 28 communicates With a delivery passage 30 which opens into an internally threaded enlargement 31 for receiving a fitting provided for attachment to a hydraulic system such for example as the hydraulic system of a trailer brake. In addition, the recess 28 is in communication through an opening through a valve seat 32 with a return passage 34 through which fluid may return to a reservoir later to be described.

Associated with the valve seat 32 is a pressure regulating valve 36 connected to the vertically slidable armature 38 of a solenoid 40, the windings of which are adapted to be connected to a voltage source variable in accordance with variations in an extraneous parameter by means of a connection 42.

Assembled tightly against the flat suface 25 of the body 10 is an intermediate flat plate 44. Attachment of the plate to the body is by assembly screws 46 of which five are provided as clearly evident in FIGURE 3. The intermediate plate 44 is provided with an opening 48 forming an inlet passage in registration with the inlet recess 26. It is provided with a second opening 50 in registration with the return passage 34. The intermediate plate 44 is additionally provided with an elongated opening 52 adapted to receive and interfit closely with a pair of pump gears 54 and 56. The pump gear 56 is keyed or otherwise fixedly secured to the motor shaft 20, and the gear 54 is rotatably supported on a pivot mounting pin 57.

Overlying and fitted against the outer flat surface of the intermediate plate 44 is a cover plate 58 having a recess 60 which receives the end of the motor shaft 20. The cover plate is secured by suitable bolts (not shown) extending through the intermediate plate 44 into tapped recesses in the body 10, thus making an integral rigid assembly of the body 10, intermediate plate 44, and cover plate 58. The cover plate 58 overlies the opening 52 in the intermediate plate and cooperates with the flat surface of the body 10 to form a closed pumping chamber in which the gears 54 and 56 are rotated.

The cover plate 58 is provided with openings (not shown) registering with the openings 48 and 50 of the intermediate plate and forming therewith inlet and return passages communicating with the interior of the reservoir later to be described.

Referring now to FIGURE 1 the reservoir is formed by a cyindrical cup 61 closed at its outer end except for an opening 62 which receives an assembly screw 64 the end of which is threaded in a boss 66 formed on the cover plate 58. The cup 60 has out-turned edge flanges 68 cooperating with O-rings, best seen in FIGURE 1, to provide a closed sealed reservoir.

Referring now to FIGURE 3 it will be observed that the inlet passage formed by registering openings including the opening 48 inthe intermediate plate and the inlet recess 26, communicate with the pump chamber at one side thereof. Similarly, the outlet recess 28 communicates with the opposite side of the pump chamber and receives the fluid delivered by the pump gears 54, 56. Fluid pumped into the recess 28 may flow through the open delivery passage 30 or it may flow through the port in the valve seat 32 to the return passage 34 as permitted by the pressure regulating valve 36. When the winding of the solenoid 40 is de-energized, the valve 36 is freely opened by pressure within the recess 28 and accordingly, the fluid returns through the passage formed by the registering ports including the port 50 to the interior of the reservoir. When however, a voltage is applied to the windings of the solenoid the valve 36 is urged downwardly as seen in FIGURE 4 with a force dependent upon the instantaneous voltage applied to the windings. The pressure in the recess 28 and in the closed system connected thereto through the delivery passage 30 then builds up until the pressure is effective to lift the valve 36 to permit escape of fluid to the return passage 34. In this way suflicient fluid is pumped into the system to which the device is connected to establish and maintain a pressure at a value determined by the values of a predetermined parameter in an extraneous system.

The motor 22 may be energized only upon attament of a predetermined value of the extraneous parameter such for example as a predetermined minimum pressure in the hydraulic system of a tractor. Alternatively, the motor may be energized by a remote switch which may for example be closed upon initial depression of the brake pedal of the towing vehicle, without reference to a build up of hydraulic pressure in the brake system. In any case, it will be observed that when the solenoid is deenergized, pressure in the system supplied by fluid from the delivery port 30 falls to approximately atmospheric pressure since pressures above atmospheric are effective on the larger area of the valve on which pressure tends to lift the valve so as to relieve pressure in the system.

A mounting bracking 70 is secured to the motor casing 24 and a second mounting bracket 72 is attached to the reservoir-forming cup 61 by means of which the complete assembly may be mounted at a convenient point. It will be observed that the pump assembly comprising the body 10, the intermediate plate 44 and the cover plate 58 are thus supported in the assembly from the motor casing 24 and the cup 61.

What we claim as our invention is:

1. A compact unitary fluid supply device for delivering fluid into an external closed system and maintaining the fluid in said system at a pressure variable in accordance with variations in an extraneous parameter which comprises a generally cylindrical pump assembly having a pump chamber therein, a motor having a generally cylindrical housing fixed at one end to one end of said pump assembly connected in driving relation to said pump assembly, a generally cylindrical reservoir having one end fixed to the other end of said pump assembly, an inlet passage connecting said reservoir to said pump chamber, a return passage from said chamber to said reservoir, a pressure regulating valve in said return passage, an open delivery passage connected to said chamber, and a solenoid connected to said valve operable when energized to urge said valve toward closed position to establish the pressure of fluid delivered from said delivery passage in accordance with the voltage applied to said solenoid.

2. A device as defined in claim 1, said body having an extension at one side thereof on which said solenoid is mounted and through which said delivery passage extends for connection to an exterior fluid system.

3. A device as defined in claim 1 in which said pump assembly comprises a generally cylindrical body having a central opening, a flat surface at one end thereof, and inlet and outlet recesses in its flat surface, an intermediate plate having an elongated pump opening having a pair of pump gears fitted therein, one of said gears being connected to said motor by a shaft extending through the said central opening, said open delivery passage and said return passage being in fluid communication with said outlet recess, and a cover plate overlying said pump plate forming an end of said reservoir and cooperating with the flat surface of said cylindrical body and the pump opening in said intermediate plate to form said pump chamber.

4. A compact unitary fluid supply device for delivering fluid into an external closed system and maintaining the fluid in said system at a pressure variable in accordance with variations in an extraneous parameter, which comprises an elongated generally cylindrical assembly having a motor provided with an elongated cylindrical housing at one end, a reservoir-forming cup of cylindrical shape at the other end, and a pump and valving assembly interposed between and connecting said motor housing and cup and closing the open end of the cup to form therewith a reservoir, the interposed assembly comprising a cylindrical body having a central opening, a flat surface at one side provided with inlet and outlet recesses, said outlet recess having an open delivery passage in communication therewith and extending to a side of said body, a return passage for returning fluid to said reservoir, and a solenoid actuated pressure regulating valve in said return passage, a flat intermediate plate fitted to the flat surface of said body having an elongated opening therethrough, and inlet and outlet passages in registration with said recesses, said motor having a drive shaft extending through the opening in said body into the opening in said intermediate plate, a drive gear fixed to said shaft, a second gear in the opening in said intermediate plate in mesh with said drive gear and forming a gear pump therewith, a cylndrical cover plate having a flat surface fitted to the side of said intermediate plate opposite said body and forming a closure for said cup, and having openings in registration with the inlet and outlet passages in said intermediate plate.

5. A device as defined in claim 4, said body having a generally radially projecting portion forming a pair of laterally facing flat surfaces, a solenoid mounted on one of said flat surfaces connected to said valve, said delivery passage opening through the other flat surface of said portion.

6. A device for delivering fluid at a predetermined pressure to an external closed system comprising a support body having a first flat surface at one end thereof and a pair of relatively angularly disposed flat surfaces at the side thereof, said body having an opening extending therethrough from end to end, inlet and outlet recesses opening into said first flat surface, said outlet recess having an open delivery passage extending to one of said pair of flat surfaces and a return passage extending to said first flat surface, a pressure regulating valve seat in said return passage facing the other of said pair of flat surfaces, a solenoid mounted on the other of said pair of flat surfaces, a pressure regulating valve connected to said solenoid and cooperating with said valve seat, an intermediate flat plate having opposed flat surfaces one of which is fitted to the said first flat surface of said body, said plate having an elongated opening therethrough in communication at opposite sides with said inlet and outlet recesses, said plate having an inlet passage therethrough in communication with said inlet recess and a return passage therethrough in communication with the return passage in said body, a pair of pump gears in said elongated opening through said plate, drive means for one of said gears extending through the opening through said body, a closure plate having a flat surface fitted against the other flat surface of said intermediate plate and cooperating with the elongated opening in said intermediate plate and the said first flat surface of said body to provide an elongated pump chamber communicating with the inlet and outlet recesses in said support body, said closure plate having an inlet passage therethrough in registration with the inlet passage in said intermediate plate and having a return passage therethrough in registration with the return passage through said intermediate plate, a cup having its open end sealed to said closure plate and forming a reservoir therewith.

7. A device as defined in claim 6 comprising a motor fixed to said support body and having its output shaft constituting the said drive means.

References Cited UNITED STATES PATENTS 2,119,740 6/1938 Fellows et al 137-'563 2,546,565 3/ 195 1 Schneider 137--565 5 2,660,336 11/1953 Coffey et :al 137569 2,725,074 11/ 1955 McLeod 137-569 2,732,168 1/1956 Greenley 137-565 3,126,030 3/ 1964 Stoermer 137569 3,247,912 4/ 1966 Reynolds 251-129 10 FOREIGN PATENTS 586,844 11/1959 Canada. 686,475 1/ 1953 Great Britain.

15 M. CARY NELSON, Primary Examiner W. R. CLINE, Assistant Examiner 

